1. Field
Embodiments relate to a secondary battery.
2. Description of the Related Art
Unlike a primary battery which is not rechargeable, a secondary battery is capable of being charged and discharged. A low-capacity secondary battery composed of a single battery cell may be used as a power source for various small portable electronic devices, e.g., cellular phones and camcorders. A high-capacity secondary battery in which a plurality of battery cells are connected to each other in a pack structure may be used as a power source for, e.g., driving a motor of a hybrid electric vehicle (HEV).
Secondary batteries may be manufactured in various shapes. Generally, secondary batteries may be classified as a cylindrical shape battery or a prismatic shape battery. The secondary battery may be formed such that an electrode assembly, including a separator as an insulator between positive and negative electrode plates, and an electrolyte are accommodated in a case. A cap assembly having electrode terminals may be provided on the case.
If excessive heat is generated in the secondary battery or the electrolyte is decomposed, an internal pressure of the battery may increase, resulting in fire or explosion.